A multi-chuck high-temperature creep test clamping device and its usage method

Abstract

The present invention discloses a clamping device for high-temperature creep test with multiple chucks and a using method. The device includes an upper clamping seat body, a test piece, a lower clamping seat body, several upper chucks and several lower chucks. The test piece is clamped between the upper clamping seat body and the lower clamping seat body by the lower chucks of the upper chucks with opposite positions. A hydraulic system and several deformation measuring devices are arranged on the upper clamping seat body. The hydraulic system includes several upper chucks, several seat cylinders and an oil storage cavity. The seat cylinders are arranged in the upper clamping seat body. The upper end of each upper chuck is located in a seat cylinder and can perform axial piston movement in the seat cylinder. The oil storage cavity arranged in the upper clamping seat body is communicated with several seat cylinders respectively through multiple channels. A deformation measuring device is fixed on each upper chuck. The present invention can not only ensure that each test piece has equal load during high-temperature creep test, but also is beneficial to the measurement of the deformation amount of a single test piece.

Description

Technical Field

[0001] The present invention relates to the technical field of material testing, and in particular, to a multi-chuck high-temperature creep test clamping device and a usage method thereof. Background Art

[0002] With the gradual maturity and rapid development of industrial technology, in the fields of aerospace, energy and power, etc., many metals need to work continuously at high temperatures, and the requirements for the high-temperature resistance performance of metal materials are getting higher and higher. Therefore, the creep rupture strength performance of metal materials has also attracted more and more attention. To evaluate the high-temperature creep rupture strength performance of metal materials, generally, a uniaxial creep test of a standard test piece needs to be carried out. Creep tests generally have the characteristics of long test time and large test tasks. However, the clamping device of a general creep testing machine can only clamp a single test piece, so the time consumption of creep tests is often huge.

[0003] To solve the above problems, in order to speed up the test progress, generally, the number of testing machines is increased. Although this method saves time costs, it causes a great waste of test funds and energy. Considering that there is generally a large margin in the rated load of the creep testing machine compared with the loading requirements of the test pieces, the test progress can be accelerated by improving the clamping device of the testing machine and increasing the number of test pieces in a single test. During the test, how to accurately measure the deformation of each test piece in real time and ensure that the load of each test piece is the same under different deformation amounts are two key problems that the clamping device needs to solve. In the prior art, in the double-chuck fixture disclosed in Chinese Patent CN113103030A "A Multi-Chuck Fixture", the piston drives the swing rod to control the tightening and loosening of the chucks on the swing rod, and this scheme cannot ensure that the loads of the two test pieces are equal during the test.

[0004] In view of the deficiencies of the prior art, it is necessary to provide a multi-chuck clamping device and a testing method with reliable structure that can simultaneously meet the requirements of equal load and measurable deformation, so as to realize the high-temperature creep test of multiple test pieces by a single creep testing machine, and achieve the purpose of saving time costs and economic costs. Summary of the Invention

[0005] To solve the above problems, the present invention provides a multi-chuck high-temperature creep test clamping device and a usage method thereof that can enable a single testing machine to simultaneously perform high-temperature creep tests on multiple test pieces.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention is a clamping device for high-temperature creep tests with multiple chucks, including an upper clamping seat body, a test piece, a lower clamping seat body, several upper chucks and several lower chucks. The test piece is clamped between the upper clamping seat body and the lower clamping seat body by the upper and lower chucks with relative positions. A hydraulic system and several deformation measuring devices are arranged on the upper clamping seat body. The hydraulic system includes several upper chucks, several seat cylinders and an oil storage cavity. The seat cylinders are arranged in the upper clamping seat body. The upper end of each upper chuck is located in a seat cylinder and can perform axial piston movement in the seat cylinder. The oil storage cavity arranged in the upper clamping seat body is communicated with several seat cylinders respectively through multiple channels. A deformation measuring device is fixed on each upper chuck.

[0008] A further improvement of the present invention lies in that: a spherical valve for controlling its on-off is arranged on each channel.

[0009] A further improvement of the present invention lies in that: the deformation measuring device includes a resistance wire and a measuring contact ring. One end of the resistance wire is fixed to the upper chuck, and the other end passes through the measuring contact ring fixed in the upper clamping seat body and contacts the conductive inner layer of the measuring contact ring.

[0010] A further improvement of the present invention lies in that: an upper sealing ring and a lower sealing ring are arranged between the upper chuck and the seat cylinder. The upper sealing ring is fixed to the upper end of the upper chuck, and the lower sealing ring is fixed to the mouth of the seat cylinder.

[0011] A further improvement of the present invention lies in that: a buffer spring is arranged at the bottom of the seat cylinder at the upper end of the upper chuck.

[0012] A further improvement of the present invention lies in that: an upper clamping rod and an oil injection hole are also arranged on the upper clamping seat body. The oil injection hole is communicated with the oil storage cavity, and the oil injection hole is blocked by an oil injection hole plug through threaded fit.

[0013] A further improvement of the present invention lies in that: a lower clamping rod and several lower seat cavities are arranged on the lower clamping seat body. In each lower seat cavity, a left lower clamping block and a right lower clamping block for cooperating with the longitudinal tree-shaped tenons of the lower chuck are arranged.

[0014] A further improvement of the present invention lies in that: a cooling system is arranged on both the upper clamping seat body and the lower clamping seat body.

[0015] A using method of the clamping device for high-temperature creep tests with multiple chucks of the present invention includes the following steps:

[0016] Step 1, rotate the spherical valve to open the channel, inject hydraulic oil from the oil injection hole to make the upper end of the upper chuck located at the middle position in the seat cylinder, tighten the oil injection hole plug, open the furnace chamber of the high-temperature furnace, clamp the lower clamping seat body in the lower chuck of the creep testing machine, and lower the lower chuck of the creep testing machine to the lowest position. Raise the upper chuck of the creep testing machine and clamp the upper clamping seat body in the upper chuck of the creep testing machine;

[0017] Step 2: Screw the lower clamping section of the test piece into the lower chuck, and then screw the upper clamping section of the test piece into the upper chuck; Step 3: Repeat Step 2 until all upper chucks / lower chucks are fixed with test pieces. Lower the upper chuck of the creep testing machine until the lower chuck is inserted between the left lower clamping block and the right lower clamping block, and through the cooperation of the longitudinal tree-shaped tenon and mortise structure, slowly increase the axial tensile force of the creep testing machine until the predetermined tensile load of the test is reached;

[0018] Step 4: Close the furnace chamber of the high-temperature furnace, set the temperature to the test temperature, start the test, and respectively introduce coolant into the upper clamping seat body and the lower clamping seat body for cooling;

[0019] Step 5: Real-time collect the tensile force F of the creep testing machine according to the set collection rate, calculate the tensile force F / N acting on each test piece based on the tensile force F, and determine the load of each test piece;

[0020] Step 6: Measure the resistance between the measurement contact ring and the top of the resistance wire at the start of the test. Through the formula: Obtain the initial length from the measurement contact ring to the top of the resistance wire, where S is the cross-sectional area of the resistance wire, ρ is the resistivity of the resistance wire. Real-time collect the length from the measurement contact ring to the top of the resistance wire according to the set collection rate, and then combine with the displacement of the upper chuck of the creep testing machine to obtain the actual deformation amount of the test piece. As the test progresses, creep curves of several test pieces under the set load are obtained simultaneously;

[0021] Step 7: If a test piece is broken, close the spherical valve corresponding to this test piece to ensure that the remaining test pieces continue the normal test until all test pieces are broken, and the test ends, and the creep performance of the corresponding material of the test piece is measured.

[0022] The beneficial effects of the present invention are as follows: The present invention can not only ensure that the load of each test piece is equal during the high-temperature creep test, but also is conducive to the measurement of the deformation amount of a single test piece. In addition, the device of the present invention is not only applicable to the clamping of high-temperature creep tests of metal materials, but also applicable to the clamping of room-temperature tensile strength tests of metal materials. Compared with the single-chuck clamping device, the device of the present invention greatly increases the number of test pieces in a single test, greatly shortens the test time, and saves a large amount of manpower and material resources. Description of the Drawings

[0023] Figure 1 is a schematic diagram of a multi-chuck high-temperature creep test clamping device in an embodiment of the present invention;

[0024] Figure 2 is a schematic diagram of the structure of the test test piece in an embodiment of the present invention;

[0025] Figure 3It is a schematic cross-sectional structure diagram of a multi-chuck high-temperature creep test clamping device in an embodiment of the present invention;

[0026] Figure 4 is Figure 3 a partial enlarged schematic diagram in;

[0027] Figure 5 It is a schematic diagram of the state where the lower chuck is inserted into the lower chuck block in an embodiment of the present invention;

[0028] Figure 6 It is a schematic diagram of the state where the lower chuck block clamps the lower chuck in an embodiment of the present invention;

[0029] Figure 7 It is a schematic diagram of the deformation measurement principle in an embodiment of the present invention;

[0030] The reference numerals are as follows: 1 - upper clamping seat body, 2 - upper chuck, 3 - test piece, 4 - lower chuck, 5 - lower clamping seat body, 6 - upper clamping section, 7 - lower clamping section, 8 - intermediate section, 9 - upper thread, 10 - lower thread, 11 - internal thread, 12 - lower sealing ring, 13 - seat body cylinder, 14 - upper sealing ring, 15 - upper clamping rod, 16 - channel, 17 - oil storage cavity, 18 - spherical valve, 19 - hydraulic oil, 20 - oil injection hole, 21 - oil injection hole plug, 22 - buffer spring, 23 - measurement touch ring, 24 - resistance wire, 25 - lower clamping rod, 26 - vertical tree-shaped tenon, 27 - lower left chuck block, 28 - lower right chuck block, 29 - lower chuck of creep testing machine, 30 - lower seat body cavity, 31 - upper chuck of creep testing machine, 32 - high-temperature furnace, 33 - upper cooling inlet, 34 - upper cooling outlet, 35 - lower cooling inlet, 36 - lower cooling outlet. Detailed implementation manners

[0031] The following details the implementation of the present invention in conjunction with the technical solutions and the drawings. However, it should be noted that these implementation manners are not limitations on the present invention, and any equivalent changes or substitutions in terms of functions, methods, or mechanisms made by those of ordinary skill in the art according to these implementation manners fall within the protection scope of the present invention.

[0032] As Figure 1 shown, a multi-chuck high-temperature creep test clamping device in this embodiment includes an upper clamping seat body 1, a test piece 3, a lower clamping seat body 5, several upper chucks 2 and several lower chucks 4. Preferably, there are three upper chucks 3 and three lower chucks 4. An upper clamping rod 15 is provided on the upper clamping seat body 1, and a lower clamping rod 25 is provided on the lower clamping seat body 5. During the test, the upper clamping seat body 1 is clamped in the upper chuck 31 of the creep testing machine through the upper clamping rod 15, and the lower clamping seat body 5 is clamped in the lower chuck 29 of the creep testing machine through the lower clamping rod 25.

[0033] As Figures 2 - 4As shown, the test piece 3 is divided into an upper clamping section 6, a lower clamping section 7, and an intermediate section 8. The upper clamping section 6 is provided with an upper thread 9, and the lower clamping section 7 is provided with a lower thread 10. The upper thread 9 is connected in a mating manner with the internal thread 11 of the upper chuck 2, and the lower thread 10 is connected in a mating manner with the internal thread of the lower chuck 4.

[0034] A hydraulic system and several deformation measuring devices are provided on the upper clamping seat body 1. The hydraulic system includes an upper chuck 2, a seat body cylinder 13, and an oil storage cavity 17. Among them, the upper end of the upper chuck 2 is located in the seat body cylinder 13, and the lower end passes through the lower sealing ring 12 fixed at the cylinder port of the seat body cylinder 13 and is located outside the seat body cylinder 13. An upper sealing ring 14 is fixed to the upper end of the upper chuck 2, and the upper sealing ring 14 can slide up and down in the seat body cylinder 13 along with the upper chuck 2. The seat body cylinder 13 is communicated with the oil storage cavity 17 through a channel 16, and the channel 16 is controlled to be opened and closed by a spherical valve 18. The cavity formed between the seat body cylinder 13 near the cylinder port and the upper chuck 2 and the oil storage cavity 17 are both filled with hydraulic oil 19. The upper end of the oil storage cavity 17 is communicated with an oil injection hole 20, and the oil injection hole 20 is plugged by an oil injection hole plug 21 through a threaded fit. A buffer spring 22 is located in the seat body cylinder 13 and fixed to the upper clamping seat body 1. When the test piece 3 is broken by pulling, the buffer spring 22 can play a buffering role to prevent the upper chuck 2 from colliding with the bottom of the seat body cylinder 13.

[0035] The deformation measuring device includes a resistance wire 24 and a measuring contact ring 23. The top end of the resistance wire 24 is point A, and the bottom end is fixed to the upper surface of the upper chuck 2. The upper end of the resistance wire 24 passes through the measuring contact ring 23 and extends into a hole in the upper clamping seat body 1. The side surface of the resistance wire 24 is in contact with the conductive inner layer of the measuring contact ring 23, and the insulating outer surface of the measuring contact ring 23 is fixed to the upper clamping seat body 1. At the beginning of the high-temperature creep test, measure the resistance R between point A of the resistance wire 24 and the measuring contact ring 23. 0 , through the formula: where S is the cross-sectional area of the resistance wire and ρ is the resistivity of the resistance wire, to obtain the initial length L from the measuring contact ring 23 to point A. 0 , in the high-temperature creep test, collect the resistance R between point A of the resistance wire 24 and the measuring contact ring 23 in real time according to the acquisition rate, calculate the length L from the measuring contact ring 23 to point A through the formula, and according to the displacement amount Ls of the upper chuck 31 on the creep testing machine, the initial length L 0 and the length L, the actual deformation amount of the test piece 3 can be obtained. The actual strain of the test piece 3 can be obtained.

[0036] The lower end of the lower chuck 4 is provided with a longitudinal tree-shaped tenon 26, and mortise grooves matching with the longitudinal tree-shaped tenon 26 are provided on the left lower chuck block 27 and the right lower chuck block 28. The left lower chuck block 27 and the right lower chuck block 28 are located in the lower seat cavity 30 of the lower clamping seat body 5. During the test, the lower clamping rod 25 of the lower clamping seat body 5 is clamped in the lower chuck 29 of the creep testing machine. After fixing the test piece 3 to the upper chuck 2 and the lower chuck 4, lower the upper chuck 31 of the creep testing machine until the lower chuck 4 is inserted between the left lower chuck block 27 and the right lower chuck block 28, and the longitudinal tree-shaped tenon 26 of the lower chuck 4 is engaged with the mortise groove to complete the fixation of the test piece 3. After the test piece 3 is fixed, place the test piece 3, the upper chuck 2 and the lower chuck 4 in the furnace. To avoid the high temperature of the fixture, the coolant enters from the upper cooling inlet 33 of the cooling system of the upper clamping seat body 1 and flows out from the upper cooling outlet 34, and the coolant enters from the lower cooling inlet 35 of the cooling system of the lower clamping seat body 5 and flows out from the lower cooling outlet 36.

[0037] In this embodiment, taking the test piece 3 made of TC17 titanium alloy material as an example, the high-temperature creep test of the test piece 3 is carried out by cooperating the above-mentioned multi-chuck high-temperature creep test clamping device with the creep testing machine to test the high-temperature creep performance of the TC17 titanium alloy material. The specific test steps are as follows:

[0038] Step 1: Rotate the spherical valve 18 to keep the channel 16 in a connected state, open the oil filling hole plug 21, inject the hydraulic oil 19 to make the upper chuck 2 and the upper sealing ring 14 located at the middle position of the seat cylinder 13, close the oil filling hole plug 21, open the furnace chamber 32 of the high-temperature furnace, clamp the lower clamping rod 25 of the lower clamping seat body 5 in the lower chuck 29 of the creep testing machine, and lower the lower chuck 29 of the creep testing machine to the lowest position. Raise the upper chuck 31 of the creep testing machine and clamp the upper clamping rod 15 of the upper clamping seat body 1 in the upper chuck 31 of the creep testing machine.

[0039] Step 2: Screw the lower clamping section 7 of the test piece 3 into the lower chuck 4 through the cooperation of the lower thread 10, and then screw the upper clamping section 6 of the test piece 3 into the upper chuck 2 through the cooperation of the upper thread 9.

[0040] Step 3: Repeat Step 2, respectively assemble the three test pieces 3 into the upper chuck 2 and the lower chuck 4, lower the upper chuck 31 of the creep testing machine until the lower chuck 4 is inserted between the left lower chuck block 27 and the right lower chuck block 28. As Figures 5 - 6 shown, after the longitudinal tree-shaped tenon-mortise groove structure is engaged, slowly raise the upper chuck 31 of the creep testing machine to make the left lower chuck block 27 and the right lower chuck block 28 rise together, and under the action of the conical lower seat cavity 30, press the lower chuck 4 tightly. Slowly increase the axial tensile force of the creep testing machine. The greater the tensile force, the tighter it is pressed until the test predetermined tensile load is reached.

[0041] Step 4: Close the furnace chamber of the high-temperature furnace 32, turn on the switch of the creep testing machine, set the temperature to the test temperature, start the test, and respectively introduce cooling liquid into the upper clamping seat body 1 and the lower clamping seat body 5 for cooling;

[0042] Step 5: Collect the tensile force F of the creep testing machine in real time according to the set acquisition rate. Since the three seat cylinders and the oil storage cavity are filled with hydraulic oil 19, according to Pascal's principle, the pressure applied to the enclosed liquid can be transmitted by the liquid to all directions without change in magnitude. Therefore, the tensile forces provided by the three upper chucks to the test piece are always equal, all being F / 3;

[0043] Step 6: As Figure 7 shown, measure the resistance R between the measurement contact ring 23 and point A in the resistance wire 24 at the start of the test 0 , and through the formula: where S is the cross-sectional area of the resistance wire and ρ is the resistivity of the resistance wire, obtain the initial length L from the measurement contact ring 23 to point A 0 , measure the resistance R between the measurement contact ring 23 and point A in the resistance wire 24 in real time according to the set acquisition rate, calculate the real-time length L from the measurement contact ring 23 to point A. The displacement Ls of the upper chuck 31 on the creep testing machine is known. Therefore, the actual deformation of the test piece 3 is: ΔL = Ls + L - L 0 , and the strain of the test piece 3 is ε = ΔL / l, where l is the original length of the middle section 8 of the test piece 3. As the test progresses, the creep curves of the three test pieces under the set load can be obtained simultaneously;

[0044] Step 7: In the case where the test piece is suddenly pulled and broken, the corresponding upper chuck 2 will also suddenly rise. However, the buffer spring 22 can protect the upper chuck 2 from hitting the upper clamping seat body 1. At this time, rotate the spherical valve 18 corresponding to this test piece to close the connection between this seat cylinder and other spaces, ensuring that the remaining test pieces continue to be tested normally until all the test pieces 3 are pulled and broken, and the test ends, and the creep performance of the TC17 titanium alloy material is measured.

[0045] The number of chucks of this device can be changed according to factors such as test requirements and the size of the furnace chamber of the high-temperature furnace. It can either adopt the three-chuck scheme exemplified in this embodiment, or adopt two-chuck, four-chuck schemes, etc.

[0046] It should be noted that the terms such as "upper", "lower", "left", "right", etc. cited in the invention are only for the convenience of description and are not used to limit the scope of implementation of the invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope of implementation of the invention.

[0047] The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present invention should be regarded as within the protection scope of the present invention.

Claims

1. A multi-chuck high-temperature creep test clamping device, comprising an upper clamping seat body (1), a test piece (3), a lower clamping seat body (5), several upper chucks (2) and several lower chucks (4), wherein the test piece (3) is clamped between the upper clamping seat body (1) and the lower clamping seat body (5) by the upper chucks (2) and the lower chucks (4) which are opposite in position. Characterized in that: A hydraulic system and several deformation measuring devices are arranged on the upper clamping seat body (1). The hydraulic system includes several upper chucks (2), several seat cylinders (13) and an oil storage cavity (17). The seat cylinders (13) are arranged in the upper clamping seat body (1). The upper end of each upper chuck (2) is located in a seat cylinder (13) and can perform axial piston movement in the seat cylinder (13). The oil storage cavity (17) arranged in the upper clamping seat body (1) is communicated with several seat cylinders (13) respectively through a plurality of channels (16). A deformation measuring device is fixed on each upper chuck (2). A spherical valve (18) for controlling its on-off is arranged on each channel (16). The deformation measuring device includes a resistance wire (24) and a measuring contact ring (23). One end of the resistance wire (24) is fixed to the upper chuck (2), and the other end passes through the measuring contact ring (23) fixed in the upper clamping seat body (1) and contacts the conductive inner layer of the measuring contact ring (23). An upper sealing ring (14) and a lower sealing ring (12) are arranged between the upper chuck (2) and the seat cylinder (13). The upper sealing ring (14) is fixed to the upper end of the upper chuck (2), and the lower sealing ring (12) is fixed to the mouth of the seat cylinder (13). A buffer spring (22) is arranged at the bottom of the seat cylinder (13) at the upper end of the upper chuck (2). An upper clamping rod (15) and an oil injection hole (20) are further arranged on the upper clamping seat body (1). The oil injection hole (20) is communicated with the oil storage cavity (17), and the oil injection hole (20) is blocked by an oil injection hole plug (21) through thread fit. A lower clamping rod (25) and several lower seat cavities (30) are arranged on the lower clamping seat body (5). A left lower clamping block (27) and a right lower clamping block (28) for cooperating with the longitudinal tree-shaped tenon (26) of the lower chuck (4) are arranged in each lower seat cavity (30). Cooling systems are arranged on both the upper clamping seat body (1) and the lower clamping seat body (5). Measure the resistance between the measurement contact ring (23) and the top of the resistance wire (24) at the start of the measurement test, using the formula: Obtain the initial length from the measurement contact ring (23) to the top of the resistance wire (24). Here, S is the cross-sectional area of the resistance wire, ρ is the resistivity of the resistance wire. Collect the length from the measurement contact ring (23) to the top of the resistance wire (24) in real time according to the set acquisition rate, and then combine it with the displacement of the upper chuck (31) on the creep testing machine to obtain the actual deformation of the test piece (3). As the test progresses, simultaneously obtain the creep curves of several test pieces (3) under the set load; If the test piece (3) is broken, the spherical valve (18) corresponding to the test piece (3) is closed to ensure that the remaining test pieces (3) continue the normal test until all test pieces (3) are broken, and the test ends, and the creep performance of the material corresponding to the test piece (3) is measured.

2. A using method of a multi-chuck high-temperature creep test clamping device, Characterized in that: It includes the following steps: Step 1: Rotate the ball valve (18) to open the channel (16), inject hydraulic oil from the oil injection hole (20) to make the upper end of the upper chuck (2) located at the middle position inside the seat cylinder (13), tighten the oil injection hole plug (21), open the furnace chamber of the high-temperature furnace (32), clamp the lower clamping seat body (5) in the lower chuck (29) of the creep testing machine, and lower the lower chuck (29) of the creep testing machine to the lowest position. Raise the upper chuck (31) of the creep testing machine and clamp the upper clamping seat body (1) in the upper chuck (31) of the creep testing machine; Step 2: Screw the lower clamping section of the test piece (3) into the lower chuck (4), and then screw the upper clamping section of the test piece (3) into the upper chuck (2); Step 3: Repeat Step 2 until all the upper chucks (2) / lower chucks (4) are fixed with the test pieces (3). Lower the upper chuck (31) of the creep testing machine until the lower chuck (4) is inserted between the left lower clamping block (27) and the right lower clamping block (28), and through the dovetail groove structure of the longitudinal tree-shaped tenon (26), slowly increase the axial tensile force of the creep testing machine until the predetermined tensile load of the test is reached; Step 4: Close the furnace chamber of the high-temperature furnace (32), set the temperature to the test temperature, start the test, and respectively introduce coolant into the upper clamping seat body (1) and the lower clamping seat body (5) for cooling; Step 5: Real-time collect the tensile force F of the creep testing machine according to the set collection rate, calculate the tensile force F / N acting on each test piece (3) based on the tensile force F, and determine the load of each test piece (3); Step 6, measure the resistance between the measurement contact ring (23) and the top of the resistance wire (24) at the start of the test, using the formula: Obtain the initial length from the measurement contact ring (23) to the top of the resistance wire (24). Here, S is the cross-sectional area of the resistance wire, ρ is the resistivity of the resistance wire. Collect the length from the measurement contact ring (23) to the top of the resistance wire (24) in real time according to the set acquisition rate, and then combine it with the displacement of the upper chuck (31) on the creep testing machine to obtain the actual deformation of the test piece (3). As the test progresses, At the same time, obtain the creep curves of several test pieces (3) under the set load; Step 7: If the test piece (3) is broken, close the corresponding ball valve (18) of the test piece (3) to ensure that the remaining test pieces (3) continue the normal test until all the test pieces (3) are broken, and the test ends, and the creep performance of the material corresponding to the test piece (3) is measured.

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